Electrical power cables are common and employed for distributing power across power grids or networks, such as when moving electricity from power generation plants to electric power consumers. Power cables are conductors and generally include a conductive core (typically copper or aluminum) optionally surrounded by one or more layers of insulating material. The conductive core includes solid cores or a plurality of twisted conductive strands constructed to carry high voltages (greater than about 50,000 Volts), medium voltages (between about 1,000-50,000 Volts), or low voltages (less than about 1,000 Volts).
Occasionally one desires to form a splice or a junction in the power cable to distribute electricity to additional branches of the grid or network. Splices are commonly employed to deliver electricity to individual homes, businesses, and/or offices. For example, a “feeder line” supplying electrical power to a group of several buildings may be spliced or branched into one or more “service lines,” each of which may be connected to one of the group of buildings being serviced. As used herein, the terms “splice” and “junction” are used interchangeably, and in each case refers to the portion of a power distribution system where an incoming cable connects to at least one outgoing cable.
Splices and junctions typically employ one or more electrical conductors. After the splice is formed and power is restored, current flowing through the feeder and service lines will heat the connector. During periods of low electrical demand, current flowing through the feeder and service lines ceases or abates, and the connector cools. Such cyclic heating and cooling can expand and contract the connector, potentially undesirably loosening the electrical connection between the connector and the feeder or service lines. Loose connector lines can reduce the electrical performance of the junction.
In addition, field operators recognize that a large number of connectors should be kept in the field inventory to accommodate as many different splice configurations as possible. A typical connector inventory, for example, can include at least five different configurations, each configuration having a different number of connection ports (i.e., one port, two ports, or six or more ports). The large number of connector variations maintained in inventory, however, yields higher inventory costs for the end user. A large connector inventory, moreover, potentially reduces productivity for the end user who must expend time selecting and locating an appropriate connector for a given individual installation.
Existing power grids and networks also change as new homes and businesses are constructed and as existing homes and businesses are renovated. The industry therefore desires connectors that maintain high-performance electrical connections, allow for easy expansion of the power distribution system and readily adapt to changing service configurations.